Grab



Patented 23, 1926.

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GRAB.

Application filed October 20, 1924. :Serial No'. 744,744.

This invention relates generally to a releasable lifting grab, and particularly to means for vunseating the standing valve in an oil well pump.

lt is one object of the invention to provide a grab ofthe character indicated that may he thrown into and out of engagement with a standing valve without unscrewing the sucker rod while disengaging the grab from the valve. lt is another object of the invention to obviate the necessity of using a garbut rod for unseating the standing valve in an voil well pump whereby a valve may be; provided in the lower end of the lpumpplunger,`

lt is another object of the invention t0 provide a grab of the character indicated that will permit the withdrawal of the plunger from the well without withdrawing the standing valve.

ln the drawing Figure 1 is a vertical transverse ,section through a portion of a well pump embodyingl my invention, parts being broken away.

Figure 2 is an edge elevation of one portion of the grab.

Figure 3 is a side elevati-ion of the same.

Figure 4 is a vertical transverse section through the fixed camv bushing forming a portion of the grab.

Figure is a diagiaininatical illustration of the two cain portions of the grab showing the movements Yof one portion relative .to the other when entering intov engagement with it and being released therefrom.. n n

Refer-ringmore particularly to 'the drawing, l showfat a pump jacket' connected at its upper end to'a discharge casingffcolumn not` shown,' thebjottonif of the jacket being fitted With `a collar' 2 provided 'fv'vith a lseat ,3 toengage ystandin-g valve 4;.

'To standing'val've '4" iscoiinected a bottoni cage 5 with a ball check valve 6 positioned therein, the upper end of the cage being provided with a threaded lug 7.

On threaded lug 7 is screwed an inverted cage element S lia-ving an internal shou er 9 and an upstanding internally threaded iiange 10. On shoulder' 9 is placed a conically spiralled spring 11 held in position by a ring 12 on its lower coil. agi'ab nut having an externally threaded flange llto engage the threaded flange 8,

'thereby holding the ring 12 and spring 11 in position and vbecoming a unitary part of the standing valve.

On ldiainetrically opposite sides of the interior surface of grab nut 1 3 are formed bosses 15-1fz These bosses are exactly alike and are 'spaced a distance apart at both ends as at 1G. On the lower edge of each boss are formed cam surfaces 17 and 18, the surface 17 forming one side of a reentrant angle 19, and surface -18 being formed on the-extreme right end of the boss substantially parallel with surface 17.

The upper edge of grab nut 13 is formed into four cam surfaces 20-21--2228 lying` at substantially the saine angleto a horizontal plane and similarlyv directed around the periphery of the nut 13 as shown. These cain surfaces 'bear a definite relation to cain surfaces 17 and 18 on bosses 15, 15a. The lower Vend of cani surface 21 for instance, lies in a` vertical line as 24 `passing a little to the left of the lower end of cam surface 17, and the lower end of cani surface 22 lies in a vertical line as passing a little to the left of the lower end of cani surface 18. Cain surfaces 23, 20, bear the saine relationship to cani surfaces 17, 18a.

At 26`is shown a valve cage and at 27 a pump plunger, both of these parts being] threaded on to a `bushing 28, the latter forming a. seat at 29 for the plunger sleeve 27. riihe bottom edge of the bushing 28 isy formed to present two diainetrically opposite and -H;-.ii i'iilarly formed and directed Caml surfaces f3() and v81 adapted -to engage and eo-op'erate with cani ysurfaces 20, 21, 22, 23 to impart a turning movement yto parts 26 to 29 inclusive. i

'- Q-Depe-nding from the center bushing` 28 yandi-in axial alignment therewith isi a lfinger 32 fiattenedonjjboth sides 'at its lower end as' *ati 313 jprovided with dianietrically 'f'cpposite and-laterally extending-i bosses 3-1-35, these bossesbei'ng forniedwith cam surfaces 36, 37 respectively, similarly arranged and oppositely directed with relation to cam surfaces 17--17'fl when .the device is assembled. These cam surfacesgO-Bl also be'ar d eiinte relations to .cam

At 13 is shown or projection 38 on the lower end of linger' rests on spring l1, the cam surface slightlyrorverhanging cam surface 21. Vhen,

therefore, pressure is applied to the grab (parts 28 to 38 inclusive) the spring 11 is depressed and the cam surfaces are advanced. with surface 30 1n engagement with cam surtace 21, this being the tirst position indicated at 39 in the diagram. Continued pressure .forces surface 30 to slide along vsurface 21 'to its lower end thereby/'rotating v.t-liegrab clockwise a, distance into the position Ll0.` The grab now being pulled upwardly the camr surface 36 engages cam sur tace 17 on boss 15 and slides along vthe same t-o the end thereoin thereby causing 'the grab and parts connected thereto to rotate a distance clockwise into the position 41. Conl v tinned raising oi the grab will litt the standing` valve from its seat and permit the desired draining ot' the well.

The draining having been accomplished, the grab is` again dropped, ythe surface 30 engaging and sliding along surface' 22 of the grab nut to its lower end, thereby again rotatingthe grab a distance to the position 42. Upon raisingthe grab again the surface 36 lengages surface 18 on boss 15 and again rotates the grab a distance to the position i3 where the Ygrab is again entirely tree from the standing valve as in original position 89.

In this operation the grabbing and releasing movements have been automatic, the only voluntary movements applied to the rgrab being verticahand the rotation ot said grab occasioned' by engagement of the several cams by the raising and lowering ot the plunger being always inone direction, clockwise,fit is impossible to unscrew any joints in theV line. i y

This construction is of such a nature that it obviates the necessity'of using a garbut rod 1ior unseating the standing valve, and a vali-'1c may be arranged in the bottom end oi." the plunger it desired.

lt iis to be understood, of course, that while Ifhave herein shown and described one specific embodiment of the invention, changes in torni, construction, and method oit. operation may be made within the scope of the' appended claims.

- I claim 1. A grab comprising a pair ot telescoping members, one member having a hooked engagement with the other, means rendered operable by the successive opposite axial movements of one member relative to the other 'forfeiiecting said hooked engagement, and means rendered operable by the successl sive opposite axial movements of the one member relative to the other for effecting thevdisengagement of said hooked members.

2. A grabV comprising a pair of telescoping members, one member having a` hooked engagement with the other, means rendered operable by the successive opposite axial movements of one member relative to the other for effecting said hookedengagement,

means rendered operable by the successive opposite axial movements oit' the one member relative to the other for effecting the disengagement ot said hooked members, and resilient means for urging the one member into hooked engagement with the other.

B. rl`he combination with a standing valve cylindrical member.Y

1. The comi. nation with a standii'ig valve otf-y a cylindrical member carried thereby having four similarly directed cams termed on vits upper edge and having two diametri'cally opposite bosses formed on its inner surface, and each boss having an upwardly extending recess in its lower. edge, and a grab'eleinent having` a pair o1 diametrically opposite similarly directed cams adapted to engage said first mentioned cams and carrying a depending linger having diametrically opposite laterally extending bosses formed thereon oii'set a distance relative to the said cams on said grab, said bosses being adapted to engage said recesses in said bosses on said cylindrical member, and resilient means for urging said second mentioned bosses intoiengagement :with said recesses. Y

GEORGE n. Meenemen, 

